Epoxy compounds are very important compounds as various kinds of chemical products typically including resins, their synthetic intermediates, and the like. As their production processes, for example, oxidation of olefin compounds with peracids such as m-chloroperbenzoic acid, peracetic acid, etc. and organic peroxides such as tert-butyl hydroperoxide, etc. has been known. However, such a process uses a peracid or an organic peroxide which is relatively expensive, requires careful handling, and further requires troublesome post-treatment after completion of the reaction. Therefore, it has been desired to develop its production process without using peracids and organic peroxides.
On the other hand, recently, hydrogen peroxide has attracted attention as a clean and excellent oxidizing agent because it is cheap, is easy to handle and further comes out harmless water after completion of a reaction. Then, various processes for producing epoxy compounds by reacting olefin compounds with hydrogen peroxide have been reported. For example, JP 11-512335 W discloses an example of the production of cyclooctene oxide by reacting cyclooctene with hydrogen peroxide using a tungsten peroxo complex catalyst whose ligand is dimethyloctadecylamine oxide. However, since this process uses chloroform as a solvent which is problematic from the viewpoints of environment as well as working, safety and health. Therefore, it has been desired to develop a process for producing an epoxide compound from an olefin compound without using a solvent which is problematic from the viewpoints of environment as well as working, safety and health